1. Field of the Invention
The present invention relates, in general, to towing or trailer hitches.
2. Description of the Art
Trailer hitches typically include a rigid frame work with a coupling structure having a hitch ball mounted therein for attachment to a mating ball socket on a trailer, mating hitch, etc. The hitch is usually semi-permanently attached to the rear of a towing vehicle by means of a horizontal tube which is secured by bolts, welds, etc., to the vehicle bumper or vehicle body structure. Aligned apertures are formed in the horizontal bar, typically centered on the longitudinal axis of the vehicle when the horizontal bar is mounted on the vehicle, to receive a longitudinally extending bar carrying the hitch ball at one end. A safety chain and a lock pin are typically associated with the longitudinal bar for releasibly mounting the bar to the horizontal tube.
When not attached to a towed vehicle, the hitch ball projects rearwardly from the vehicle bumper. This creates a potentially hazardous obstacle which can cause painful injury to an individual walking behind the vehicle in close proximity to the bumper.
To illuminate this problem, as well as during lengthy time periods where the hitch is not expected to be used, the slide bar and the hitch ball are removed from the horizontal tube on the vehicle. However, due to the relatively small size of the slide bar and the hitch ball, it is common for the user to forget where he or she placed the slide bar when the hitch is to be used again.
In order to circumvent these problems, trailer hitches have been devised in which the slide bar and hitch ball are permanently attached to the horizontal tube; but are movable between an extended use position rearward of the vehicle bumper and a storage position under the vehicle body or bumper and not extending outward a significant distance beyond the vehicle bumper. Such so-called "retractable trailer hitches" are constructed to move the slide bar and hitch ball in a horizontal, longitudinal direction between the storage and extended, use positions, laterally through a horizontal plane in which the slide bar may be disposed at any angle with respect to the longitudinal centerline of the vehicle, as well as vertically pivotal about a horizontal, laterally extending axis parallel to the horizontal tube in which the slide bar pivots 180.degree. between the extended position and a storage position underlying the vehicle underbody.
For example, U.S. Pat. No. 2,838,327 discloses a retractable trailer hitch having a tubular housing welded to a transverse bar secured to a trailer or vehicle, such as by a bracket, to or below the vehicle bumper. A tubular hitch bar is telescopingly, slidably mounted within the tubular housing and carries a hitch ball at an outer end. The slidable hitch bar is rotatable 90.degree. from a first position in which the hitch ball projects vertically upward to a storage position wherein the hitch ball extends laterally to the side of the tubular housing and the slidable hitch bar is telescoped within the tubular housing. In this retracted, storage position, the hitch ball engages an open ended recess formed on one end of the tubular housing. A spring loaded bolt is carried in the tubular housing and is engageable with one of two spaced apertures in the tubular housing and the slidable member to lock the slidable member in either of the first or second positions.
During such slidable extension and retraction, the slidable bar is freely rotatable in any direction about its longitudinal axis. Thus, care must be taken in properly rotating the slide bar in the proper direction and to the proper angular position for alignment of the lock bolt with the aligned apertures in the slide bar and the tubular housing.
U.S. Pat. No. 2,671,674 discloses a similar retractable trailer hitch. In this hitch, a strap bar is secured longitudinally to the vehicle and carries a tubular casting. A draft bar or shaft is telescopingly mounted within the tubular casting and has one flattened end carrying a ball hitch. Longitudinal extension and retraction of the shaft between two positions is stopped at end limits by the ball hitch and a washer carried on the other end of the draft bar.
A pair of lugs extend from one side of the casting and pivotally carry the elongated rod which is pivoted at a center position to the lugs. One end of the rod is pivotally connected to one end of a pin which passes through an opening in the casting and enters a hole in the draft bar to lock the draft bar against movement. In this position, the ball hitch is disposed in a vertical position spaced rearwardly of the bumper.
The opposite end of the rod is pressed away from the casting by a coil spring. Another aperture is formed in the draft bar at right angles to the first aperture and is spaced therefrom. In this manner, when the rod is pressed inward toward the casting against the resilience of the spring, the pin is withdrawn from the first aperture in the draft bar to free the draft bar for sliding movement. The draft bar can then be rotated 90.degree. to bring the ball hitch horizontal and below the bumper so that the draft bar can be pushed ahead allowing the ball to pass under the bumper to a storage position. When the flattened part on the draft bar contacts one end of the casting, one of the apertures in the draft bar will be aligned with the pin for engagement of the pin with the aperture as pressure on the rod is released to lock the rod 24 in the draft bar against further movement.
While this latter hitch provides a retractable and extendable slide bar, with positive locking in both of the extended and retracted positions, the lock mechanism is complicated with respect to the number of separate parts employed in the complete trailer hitch assembly.
Thus, it would be desirable to provide a retractable trailer hitch which enables the ball hitch to be maintained on the slide bar in both the extended and retracted positions without requiring the ball hitch to be removed from the vehicle when the trailer hitch slide bar is moved to the storage, retracted position. It would also be desirable to provide a retractable trailer hitch which is simple in construction with a minimal number of components.